Add script to install emacs

scripts/install-emacs.sh

@@ -0,0 +1,48 @@
+#! /usr/bin/env bash
+set -e
+
+PREFIX="/opt/emacs"
+
+help() {
+  echo "usage: ./install-emacs.sh <VERSION>"
+}
+
+install() {
+  local version="$1"
+  mkdir -p /tmp/emacs-src
+  cd /tmp/emacs-src
+  if [ ! -d "emacs-${version}" ]; then
+    if [ ! -f "emacs-${version}.tar.gz" ]; then
+      wget "http://ftp.gnu.org/gnu/emacs/emacs-${version}.tar.gz"
+    fi
+    tar -zxf "emacs-${version}.tar.gz"
+  fi
+  cd "emacs-${version}"
+  ./configure --prefix="$PREFIX" && make && sudo make install
+}
+
+deps() {
+  sudo apt-get update
+  sudo apt-get install -y \
+       build-essential libx11-dev xaw3dg-dev libjpeg-dev libpng12-dev \
+       libgif-dev libtiff4-dev libncurses5-dev libxft-dev librsvg2-dev \
+       libmagickcore-dev libmagick++-dev libxml2-dev libgpm-dev \
+       libghc-gconf-dev libotf-dev libm17n-dev libgnutls-dev
+}
+
+main() {
+  local command="$1"
+
+  if [ -z "$command" ]; then
+    echo "$(help)" 1>&2
+    exit 1
+  fi
+
+  if [ "$command" == "deps" ]; then
+    deps
+  else
+    install "$command"
+  fi
+}
+
+main $@